My daughter is six years old and was diagnosed type�1 about a year ago. She takes two shots a day of combined NPH and Regular. I recently read a book, printed in 1997, that said that the average of blood glucose levels determined by the hemoglobin A1c test, not whether you have periods of highs and lows, determines the long-term complications. Is there any updated information on this?

The HbA1c value reflects the amount of glucose that is bound to the hemoglobin molecule, and there have been several studies which relate average blood sugar levels to the A1c. However, glycosylation of hemoglobin, itself, is of no physiological importance except as a mirror of the related linking of glucose to other proteins that form the walls of small blood vessels especially in the eye and the kidney. Increased glycosylation in these situations, over time, will produce structural and functional changes which are the basis of complications.

The exact biochemical mechanisms underlying all this are very complex, but you may come to read of AGE’s (Advanced Glycation End products) which are smaller molecules that play a part in effecting these changes and which can be measured in the serum. Day to day fluctuations in blood sugars obviously do affect A1c levels. It almost impossible to interpret their significance unless you can calculate an average concentration of blood glucose which is of course what the A1c does.

DOB